{"id":729,"date":"2023-02-26T15:39:04","date_gmt":"2023-02-26T07:39:04","guid":{"rendered":"https:\/\/www.appblog.cn\/?p=729"},"modified":"2023-04-29T17:11:10","modified_gmt":"2023-04-29T09:11:10","slug":"recreate-and-restore-activity","status":"publish","type":"post","link":"https:\/\/www.appblog.cn\/index.php\/2023\/02\/26\/recreate-and-restore-activity\/","title":{"rendered":"Activity\u7684\u91cd\u5efa\uff08recreate\uff09\u4e0e\u6062\u590d"},"content":{"rendered":"

\u5173\u4e8eActivity\u7684\u91cd\u5efa\u53ef\u4ee5\u4ece\u4ee5\u4e0b\u4e09\u4e2a\u65b9\u9762\u53bb\u4e86\u89e3\uff1a<\/p>\n

Activity\u4f1a\u51fa\u73b0\u91cd\u5efa\u7684\u4e09\u79cd\u60c5\u51b5<\/h2>\n

<\/p>\n

    \n
  1. \u7cfb\u7edf\u5185\u5b58\u4e0d\u8db3\uff1aActivity\u7cfb\u7edf\u4f1a\u6740\u6b7b\u4e00\u4e2a\u8fdb\u7a0b\uff0c\u5728\u7cfb\u7edf\u9700\u8981\u91ca\u653e\u5185\u5b58\u7684\u65f6\u5019\uff0c\u800c\u4f4d\u4e8e\u8fdb\u7a0b\u5185\u7684Activity\u5c31\u4f1a\u88ab\u9500\u6bc1\u3002\u5728\u7528\u6237\u91cd\u65b0\u56de\u5230\u8fd9\u4e2aActivity\u7684\u65f6\u5019\uff0c\u8fd9\u4e2aActivity\u5c31\u4f1a\u88ab\u91cd\u5efa<\/li>\n
  2. Configuration Change\uff08Activity\u6a2a\u7ad6\u5c4f\u5207\u6362\uff0c\u8fdb\u5165\u591a\u7a97\u53e3\u6a21\u5f0f\uff09\uff1a\u5728\u6a2a\u7ad6\u5c4f\u5207\u6362\u65f6\uff0c\u7cfb\u7edf\u4e3a\u4e86\u8c03\u6574\u5e03\u5c40\u9002\u5e94\u65b0\u7684\u914d\u7f6e\uff0c\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u4f1a\u91cd\u5efaActivity<\/li>\n
  3. \u8c03\u7528Activity\u7684onCreate()<\/code>\u65b9\u6cd5\uff1a\u4e3b\u9898\u6216\u8bed\u8a00\u5207\u6362\u65f6\u53ef\u4ee5\u8c03\u7528onCreate\u91cd\u5efaActivity\u4f7f\u65b0\u7684\u4e3b\u9898\u751f\u6548<\/li>\n<\/ol>\n

    Activity\u5728\u91cd\u5efa\u65f6\u7684\u72b6\u6001\u53d8\u5316<\/h2>\n

    \u9996\u5148\u6211\u4eec\u901a\u8fc7\u4e00\u6bb5\u7b80\u5355\u4ee3\u7801\u6765\u770b\u4e00\u4e0b\u91cd\u5efa\u8fc7\u7a0bActivity\u7684\u72b6\u6001\uff1a<\/p>\n

    public class LifeCycleActivity extends AppCompatActivity {\n\n    private static final String TAG = LifeCycleActivity.class.getName();\n\n    private static final String KEY_TEST = "test";\n\n    @Override\n    protected void onCreate(Bundle savedInstanceState) {\n        super.onCreate(savedInstanceState);\n        setContentView(R.layout.activity_life_cycle);\n        TextView tvContent = findViewById(R.id.tv_content);\n        if (savedInstanceState == null) {\n            Log.i(TAG, " ---> first time onCreate");\n        } else {\n            Log.i(TAG, " ---> recreate");\n            String test = savedInstanceState.getString(KEY_TEST);\n            tvContent.setText(test);\n        }\n\n        findViewById(R.id.btn_start).setOnClickListener(new View.OnClickListener() {\n            @Override\n            public void onClick(View view) {\n                recreate();\n            }\n        });\n    }\n\n    @Override\n    protected void onStart() {\n        super.onStart();\n        Log.i(TAG, " ---> onStart");\n    }\n\n    @Override\n    protected void onResume() {\n        super.onResume();\n        Log.i(TAG, " ---> onResume");\n    }\n\n    @Override\n    protected void onPause() {\n        super.onPause();\n        Log.i(TAG, " ---> onPause");\n    }\n\n    @Override\n    protected void onStop() {\n        super.onStop();\n        Log.i(TAG, " ---> onStop");\n    }\n\n    @Override\n    protected void onDestroy() {\n        super.onDestroy();\n        Log.i(TAG, " ---> onDestory");\n    }\n\n    @Override\n    protected void onRestart() {\n        super.onRestart();\n        Log.i(TAG, " ---> onRestart");\n    }\n\n    @Override\n    protected void onSaveInstanceState(Bundle outState) {\n        super.onSaveInstanceState(outState);\n        outState.putString(KEY_TEST, "testing");\n        Log.i(TAG," ---> onSaveInstanceState");\n    }\n\n    @Override\n    protected void onRestoreInstanceState(Bundle savedInstanceState) {\n        super.onRestoreInstanceState(savedInstanceState);\n        String test = savedInstanceState.getString(KEY_TEST);\n        Log.i(TAG, " ---> onRestoreInstanceState");\n    }\n}<\/code><\/pre>\n
    App\u8fd0\u884c\u4e4b\u540e\u5207\u6362\u6a2a\u7ad6\u5c4f\uff0c\u901a\u8fc7\u4e0a\u9762\u4ee3\u7801\u5b9e\u9a8c\u5f97\u5230\u7684\u7ed3\u679c\u662f\uff1a<\/p>\n
    I\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> first time onCreate\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onStart\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onResume\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onPause\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onSaveInstanceState\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onStop\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onDestory\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> recreate\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onStart\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onRestoreInstanceState\nI\/cn.appblog.activitylifecycle.LifeCycleActivity: \u00a0---> onResume<\/code><\/pre>\n
    \u5728\u8fdb\u5165paused\u72b6\u6001\u4e4b\u540e\uff0c\u4f1a\u8c03\u7528onSaveInstanceState<\/code>\u53bb\u4fdd\u5b58\u9700\u8981\u7684\u6570\u636e\u72b6\u6001\uff0c\u5728\u91cd\u5efa\u7684\u65f6\u5019\u53ef\u4ee5\u5728onCreate<\/code>\u548conRestoreInstanceState<\/code>\u4e2d\u7684\u53c2\u6570\u53bb\u83b7\u53d6\u9500\u6bc1\u524d\u4fdd\u5b58\u7684\u6570\u636e\u3002<\/p>\n
    Activity\u7684\u72b6\u6001\u6062\u590d<\/h2>\n
    \u5728\u4e00\u4e9b\u573a\u666f\u4e0b\u4f60\u7684Activity\u662f\u88ab\u6b63\u5e38\u7684\u9500\u6bc1\uff0c\u5f53\u7528\u6237\u6309\u4e0b\u8fd4\u56de\u952e\uff0c\u6216\u8005Activity\u5185\u90e8\u8c03\u7528finish()<\/code>\u65b9\u6cd5\uff0c\u5728\u7528\u6237\u548c\u7cfb\u7edf\u7684\u89c2\u5ff5\u4e2d\u8fd9\u4e2aActivity\u7684\u5b9e\u4f8b\u662f\u5df2\u7ecf\u4e0d\u518d\u9700\u8981\u4e86\u3002\u5728\u8fd9\u4e9b\u573a\u666f\u4e0bActivity\u7684\u9500\u6bc1\uff0c\u4e0d\u9700\u8981\u505a\u5176\u4ed6\u989d\u5916\u7684\u5de5\u4f5c\u3002\u4f46\u662f\u5982\u679c\u7cfb\u7edf\u9500\u6bc1Activity\u662f\u7531\u4e8e\u7cfb\u7edf\u7684\u9650\u5236\uff08configuration\u548cmemory pressure\uff09\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b\u4e3a\u4e86\u4fdd\u6301\u7528\u6237\u7528\u6237\u4f53\u9a8c\uff0c\u6211\u4eec\u9700\u8981\u5728\u7528\u6237\u56de\u5230Activity\u65f6\u6062\u590dActivity\u7684\u72b6\u6001\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5c3d\u7ba1Activity\u7684\u5b9e\u4f8b\u5df2\u7ecf\u6d88\u5931\uff0c\u4f46\u662f\u7cfb\u7edf\u4f1a\u8bb0\u4f4fActivity\u7684\u5b9e\u4f8b\u66fe\u7ecf\u5b58\u5728\u8fc7\u3002\u5982\u679c\u7528\u6237\u5c1d\u8bd5\u91cd\u65b0\u56de\u5230Activity\u7684\u65f6\u5019\uff0c\u7cfb\u7edf\u4f1a\u4f7f\u7528Activity\u5728\u88ab\u9500\u6bc1\u65f6\u4fdd\u5b58\u7684\u72b6\u6001\u548c\u6570\u636e\u53bb\u521b\u5efa\u4e00\u4e2a\u65b0\u7684Activity\u5b9e\u4f8b\u3002<\/p>\n
    \u7cfb\u7edf\u7528\u6765\u6062\u590d\u4e4b\u524d\u7684\u72b6\u6001\u800c\u4fdd\u5b58\u7684\u6570\u636e\u53eb\u505ainstance state\uff0c\u662f\u5b58\u50a8\u5728Bundle\u4e2d\u7684\u952e\u503c\u5bf9\u96c6\u5408\u3002\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u7cfb\u7edf\u4f7f\u7528Bundle\u6765\u5b58\u50a8layout\u4e2dView\u7684\u72b6\u6001\uff08\u4f8b\u5982\u5728EditText\u4e2d\u8f93\u5165\u7684\u4fe1\u606f\uff09\uff0c\u786e\u4fddActivity\u91cd\u5efa\u65f6\u80fd\u6062\u590d\u5230\u4e4b\u524d\u7684\u72b6\u6001\u3002\u4f60\u4e5f\u53ef\u4ee5\u7528\u6765\u5b58\u50a8\u4e00\u4e9b\u4f60\u60f3\u8981\u5728\u91cd\u5efa\u65f6\u6062\u590d\u7684\u4fe1\u606f\uff0c\u4f8b\u5982\u4e00\u4e9b\u6210\u5458\u53d8\u91cf\u7684\u503c\u548c\u7528\u6237\u7684\u8fdb\u5ea6\u4fe1\u606f\u3002<\/p>\n
    ps\uff1a\u4e3a\u4e86\u786e\u4fdd\u7cfb\u7edf\u80fd\u591f\u6062\u590d\u4f60Activity\u4e2dView\u7684\u72b6\u6001\uff0c\u6bcf\u4e00\u4e2aView\u90fd\u9700\u8981\u6709\u4e00\u4e2a\u72ec\u7279\u7684id\uff08\u901a\u8fc7 android:id<\/code> \u5c5e\u6027\u5b9a\u4e49\uff09<\/p>\n
    \u4f46\u662fBundle\u4e0d\u9002\u5408\u7528\u6765\u4fdd\u5b58\u5927\u91cf\u7684\u6570\u636e\uff0c\u56e0\u4e3a\u6570\u636e\u5728\u4fdd\u5b58\u65f6\u9700\u8981\u5728\u4e3b\u7ebf\u7a0b\u4e2d\u5e8f\u5217\u5316\uff0c\u4f1a\u6d88\u8017\u7cfb\u7edf\u5185\u5b58\u3002\u5982\u679c\u6709\u6bd4\u8f83\u591a\u7684\u6570\u636e\u9700\u8981\u4fdd\u5b58\u65f6\u53ef\u4ee5\u7ed3\u5408\u672c\u5730\u5b58\u50a8\u3002<\/p>\n
    View\u7684\u72b6\u6001\u7cfb\u7edf\u4f1a\u81ea\u52a8\u4fdd\u5b58\u6211\u4eec\u4e0d\u9700\u8981\u505a\u989d\u5916\u7684\u64cd\u4f5c\uff0c\u4f46\u662f\u6709\u5176\u4ed6\u6570\u636e\u9700\u8981\u5b58\u50a8\u65f6\u53ef\u4ee5\u91cd\u5199onSaveInstanceState<\/code>\u65b9\u6cd5\uff1a<\/p>\n
    @Override\nprotected void onSaveInstanceState(Bundle outState) {\n    super.onSaveInstanceState(outState);\n    outState.putString(KEY_TEST, "testing");\n    Log.i(TAG," ---> onSaveInstanceState");\n}<\/code><\/pre>\n
    \u6570\u636e\u5728onCreate<\/code>\u6216onRestoreInstanceState<\/code>\u4e2d\u6062\u590d\uff1a<\/p>\n
    @Override\nprotected void onCreate(Bundle savedInstanceState) {\n    super.onCreate(savedInstanceState);\n    setContentView(R.layout.activity_life_cycle);\n    TextView tvContent = findViewById(R.id.tv_content);\n    if (savedInstanceState == null) {\n        Log.i(TAG, " ---> first time onCreate");\n    } else {\n        Log.i(TAG, "recreate");\n        String test = savedInstanceState.getString(KEY_TEST);\n        tvContent.setText(test);\n    }\n\n    findViewById(R.id.btn_start).setOnClickListener(new View.OnClickListener() {\n        @Override\n        public void onClick(View view) {\n            recreate();\n            Intent intent = new Intent(LifeCycleActivity.this, SecondActivity.class);\n            startActivity(intent);\n        }\n    });\n}\n\n@Override\nprotected void onRestoreInstanceState(Bundle savedInstanceState) {\n    super.onRestoreInstanceState(savedInstanceState);\n    String test = savedInstanceState.getString(KEY_TEST);\n    Log.i(TAG, "onRestoreInstanceState");\n}<\/code><\/pre>\n
    onSaveInstanceState<\/code>\u65b9\u6cd5\u5e76\u4e0d\u662f\u6bcf\u6b21\u90fd\u4f1a\u5728onPause\u4e4b\u540e\u88ab\u8c03\u7528\uff0c\u5982\u679cActivity\u662f\u88ab\u660e\u786e\u7684close\uff08\u7528\u6237\u70b9\u51fb\u8fd4\u56de\u6309\u94ae\uff09\u6216\u8005\u8c03\u7528finish\u65f6\uff0conSaveInstanceState<\/code>\u4e0d\u4f1a\u88ab\u8c03\u7528\u3002<\/p>\n
    \u5982\u679c\u9700\u8981\u6301\u4e45\u5316\u6570\u636e\uff0c\u5982\u4fdd\u5b58\u5230preference\u6216database\uff0c\u6700\u4f73\u9009\u62e9\u662fActivity\u5728\u524d\u53f0\u7684\u65f6\u5019\u53bb\u4fdd\u5b58\uff0c\u5982\u679c\u6ca1\u6709\u8fd9\u6837\u7684\u673a\u4f1a\u53ef\u4ee5\u5728onStop\u65b9\u6cd5\u4e2d\u53bb\u4fdd\u5b58\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
    \u5173\u4e8eActivity\u7684\u91cd\u5efa\u53ef\u4ee5\u4ece\u4ee5\u4e0b\u4e09\u4e2a\u65b9\u9762\u53bb\u4e86\u89e3\uff1a Activity\u4f1a\u51fa\u73b0\u91cd\u5efa\u7684\u4e09\u79cd\u60c5\u51b5 \u7cfb\u7edf\u5185\u5b58\u4e0d\u8db3\uff1aAc […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[61],"tags":[60],"class_list":["post-729","post","type-post","status-publish","format-standard","hentry","category-android-basic","tag-activity"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/729","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/comments?post=729"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/729\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=729"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=729"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=729"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}